// Tencent is pleased to support the open source community by making RapidJSON
// available.
//
// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All
// rights reserved.
//
// Licensed under the MIT License (the "License"); you may not use this file
// except in compliance with the License. You may obtain a copy of the License
// at
//
// http://opensource.org/licenses/MIT
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.

#ifndef RAPIDJSON_INTERNAL_STRFUNC_H_
#define RAPIDJSON_INTERNAL_STRFUNC_H_

#include <cwchar>
#include "../stream.h"

RAPIDJSON_NAMESPACE_BEGIN
namespace internal {

//! Custom strlen() which works on different character types.
/*! \tparam Ch Character type (e.g. char, wchar_t, short)
    \param s Null-terminated input string.
    \return Number of characters in the string.
    \note This has the same semantics as strlen(), the return value is not
   number of Unicode codepoints.
*/
template <typename Ch>
inline SizeType StrLen(const Ch *s) {
  RAPIDJSON_ASSERT(s != 0);
  const Ch *p = s;
  while (*p) ++p;
  return SizeType(p - s);
}

template <>
inline SizeType StrLen(const char *s) {
  return SizeType(std::strlen(s));
}

template <>
inline SizeType StrLen(const wchar_t *s) {
  return SizeType(std::wcslen(s));
}

//! Returns number of code points in a encoded string.
template <typename Encoding>
bool CountStringCodePoint(const typename Encoding::Ch *s, SizeType length,
                          SizeType *outCount) {
  RAPIDJSON_ASSERT(s != 0);
  RAPIDJSON_ASSERT(outCount != 0);
  GenericStringStream<Encoding> is(s);
  const typename Encoding::Ch *end = s + length;
  SizeType count = 0;
  while (is.src_ < end) {
    unsigned codepoint;
    if (!Encoding::Decode(is, &codepoint)) return false;
    count++;
  }
  *outCount = count;
  return true;
}

}  // namespace internal
RAPIDJSON_NAMESPACE_END

#endif  // RAPIDJSON_INTERNAL_STRFUNC_H_
